Oil well drilling drawworks



Nov. 29, 1955 s. w. WEBSTER 2,725,213

OIL WELL DRILLING DRAWWORKS Filed April 16, 1951 IN VEN TOR. SAMUEL M4WEBSTER. DECEASED. 5) /DA E. M ELVY WEBSTER, EXECUTE/X.

United States Patent Ofiice 2,725,213 Patented Nov. 29, 1955 1 2,725,213OIL WELL DRILLING DRAWWORKS Samuel W. Webster deceased late of DallasTex b Ida E. McElvy Vlebster, eriecutrix, Dallas, Tex as signer to EmscoManufacturing Company, Los Angeles, Cal1f., a corporation of CaliforniaApplication April 16, 1951, Serial No. 221,159 5 Claims. (Cl. 254187)This invention relates in general to well drilling equipment and relatesin particular to a drawworks for deep Well drilling. y

In' the drilling of Wells to great depth, for example from 16,000 feetto 20,000 feet, a number of restrictin factors have been encountered.One of these was strength of drill pipe. This restriction has beensatisfactorily overcome by improvement in the strength and durability ofdrill pipe intended for deep well drilling. Another restric'ting factoris extreme wire line wear resulting princ ipally' from the destructiveaction of one layer of wire l ne superimposed upon another layer on thespooling drum of the drawworks. invention to provide a rotary drawworkshaving a number of simplifications and improvements over existingdrawworks and which eliminates the extreme" wire line wear mentioned inthe foregoing.

It is an object of the invention to provide a drawworks havmga drum orspool, of a size to accommodate in a single layer the spooling portionof a cable or wire line comprising a part of the hoisting apparatus ofthe derrick. In derriclts employed for deep drilling of Wells it isalmost universally the practice to use hoisting equipment comprising ablock and tackle arrangement consisting-of a crownblcck and a'travelling block interconnected bya plurality of loops of a continuouscable. One end of this wire line is connected to an anchor in one cornerof It is an object of the present of brake bands or brake rims does notrequire removal of spool since the brake mechanism is not mounted on theends of the spool. The gear through which the spool is driven isconnecteddirectly thereto and the spool may be-keyed' onto a shaft whichrotates in bearings, which" bearings maybe replaced as becomes necessarywithout removal of the spool from its position in* the drawworksstructure.

A further object of the inventionis to provide a draW-" works for deepwell drilling which do not require acable guide for controlling thespooling of the line on the spool. The spool is of such diameter andsuch length that the spooling portion of the line is wound on the spoolso as to lie in a single layer resting in a continuous helical chanhe]in the cylindric wall of the spool. This arrangementlends itself to theuseofa control which will automatically stop the rotation of the spoolat either limit ofthe spooling or unspooling of the line thereon. Withthis arrangement it is impossible for the driller to inadvertently causethe travelling block tonbump the crown block.

Further objects and advantages of the invention will be brought out inthe following part of the specification wherein in detail is describedapreferred embodiment of the invention for purpose of disclosure withoutlimiting. the scope of the invention or the range of equivalenceembraced'in the accompanying claims;

Referringv to the drawing which is for illustrative pur poses only: I

Fig. 1 isa schematic elevational view showing a heavy dutydrawworks,according to the invention in a derrick; and

'Fig. 2 is a:- plan view, to enlarged scale, showing the mechanicalelements of the drawworks, without the lions the derrick and the otherend ofthe wire line is connected to a spool so as to be wound there mThe spoolingportion of the line, therefore, is that por-' tion of theline which must be wound onto the spool in order to raise the travellingblock a predetermined distance in the derrick. In an 186 foot derrickhaving ten lines, or five complete cable loops connecting the groundblock and the travelling block, theisp'o'oling portion of the line maybe about 1,800 feet. It isan object of the invention to provide adrawworks'wherein there is a spool capable of carrying the spoolingportion of the linein a single layer on the spool so that the're' neverexists a'condition wherein one turn of the" line rides on anoth'er t'urnof the line, this spool being driven through a relatively high speedshaft which is" directly connected to the spool through a s'tepdowntransmission, such as a relatively small pinion" driving a larger gearwhich is connected to the spool, there being a brake to-control thespeed of the s,iian and thereby control the s'pee'd' of the spool.

Irf thisariang'e'rtient a brake of relatively small size as compared tothe diameter of the'spobl, may be employed,

and this'brak'e' may be" placed with rel'ation to an end r 0f the highspeed shaft so as to be expedientl'y e uipped with a brali'e'rirhcooling system.

It the anobje'ct of the'invention to provide anew work's having a drumof the character" described in the foregetirg; in which draww'orks apower ab'sb'fheflgs'ii'ch as a indignant brake, is connected to thespo'ounren g'h arra'nsniission air'ange'cl so that the rotating par letthe power absorber rotate at a' speed much higher than the speed of thespool. Not only is it possible to use a hydromatic Brake or other powerabsorber ofsmaller size, but the sensitivity ofth'e control exeited bythe power absorber isincreased.

1" It is an object of the invention to provide a' difawworks? ofsimplified construction wherein removal of thisfibbl is-never necessary.For example, replacement ing employed to shield the mechanicalelement's. H

In Fig. l a drawworks 10 is shown mounted at one side of a derrick 11having a crown block 12 at its" upper end. This crown block 12 comprisespart of the hoisting equipment for the derrick, which hoisting equipmentincludes a travelling block-13 and a steel cable or wire line 14. Thetravelling block 13 is shown with a liftinglmeans consisting of a hook15 engaging a-ro'tary swivel 16. from which'a Kelly bar 17; isconnected.

As shown in Figs: 1 and 2,. the drawworks 10 has a spool-18 on which aportion 19 of the line 14 is wound. As this portion 19 of the line 14 iswoundupon the spool 18;. the line 14-- will be pulled outof the derrick1 1, lifting the-travelling block 13 within the derrick. Likef wise,whenthe portion 19 of the line 14 is'uns'pooled from the spool. 18 itwill be fed over the crown block 12 into the derrick 1 1 ,tl1e'rebylowering the travelling block 13'Wllhl1'1 ih8 derrick 11. It willbelunderstood' that in order to lift the travelling block 13 from itslowest predetermined, point in the derrick to its highest position inthe derrick will require winding of a. related length of'line onto thespool 1-8 Hereinthis length of line is referred toyas the spoolingportion of the line sinceit is that portion of the line which winds ontoand off of the spool in causing. movement of the travellingblocklSfromone extreme position in the derrick-11 to the other extreme positiontherein. v

As shown in Fig. 2-, the spool 18 has a cylindric wall 20 with a helicalgroove 21 having a length gr'ea'te'i" than the length of the spoolingportion of the line 14, orhavin'g' alength at least aslong as the lengthof the spooling portion of the line 14 so that when the entire length ofthe spooling portion of the-line 14 is wound on the spool 18, it'will'bedisposed in asingle layer on the wall 20 of the sm lls, arid no mm ofthe line will lie upon or ress radiallyjnwardly upon another turn of theline on' the spool 18.

stub" shaft elements 22 projecting frorn'theeiids thereof into bearings23. A so-called highspeed shaft 24 is mounted adjacent the drum 18 and adrive connection is provided between this shaft 24 and the drum 18, suchdrive connection being shown as a pinion 25 fixed on the shaft 24 andbeing arranged to drive the larger gear 26 which is fixed on an end ofthe spool 18. The shaft 24 is mounted in bearings 27 and is arranged tobe driven at different selected speeds from a line shaft 28 which may bedriven from a power source through chain 29 and sprocket 30.

Sprockets 31, fixed on the end 32 of the shaft 28 through chains 35drive sprockets 33 which are turnable on the near end of the shaft 24.An air operated clutch 34 is arranged to connect the sprockets 33 to theshaft 24, thereby driving the shaft 24 at one speed. In order that theshaft 24 may be driven at another speed from the shaft 28, a dualsprocket 36 is turnably mounted on the far end of the shaft 28 and anair operated clutch 37 is provided for connecting the dual sprocket 36directly to the shaft 28 so that it will be rotated thereby.

Chains 38 are arran ed to drive a dual sprocket 39 which is fixedon theshaft 24 adjacent the pinion 25. Brake drums 40 are fixed on the far endof the shaft 24 and brake bands or shoes 41 are disposed around thesedrums 40 in the customary manner so as to provide means for producing africtional braking action or actual stopping of the shaft 24 at any timedesired. A clutch element 42 is mounted at the far end of the shaft 24.This clutch element rotates with the shaft 24 and is adapted to engagethe clutch element 43 of a power absorbing device 44, such as ahydromatic brake, operative during the time a string of drill pipe isbeing lowered and during which time the cable portion 19 is beingunwound from the drum 18. The power absorber 44 exerts a reacting forceto reduce the speed of the shaft 24 during the unwinding of cable fromthe drum 18, thereby minimizing wear upon the frictional parts of thebrake elements 40 and 41.

A further advantage of this drawworks is the arrangement which makespossible the placing of the catheads 45 forwardlv in the drawworkstructure as shown in Fig. l. A further feature of the drawworks is inthe arran ement of the large diameter drum so that the line 19. Fig. l,is taken off from the backside of the spool 18 and extends up the rearbase of the derrick 11 instead of within the derrick. This leaves aspace at the front of the drawworks for the cathead shaft 46, Fig. 2,above the rightward portion of the spool 18. Chain and s rocket means 47are rovided for driving the catshaft 46 from the line shaft 28, a clutch48 being provided for connecting the chain and sprocket means 47 to theshaft 28. For driving a rotarv machine 49, mounted on the floor of thederrick, drive shaft 50 is provided which extends to a gear box 51mounted within the drawwork structure. Power for rotation of the shaft50 is carried from the line shaft 28 to the gear box 51 through a chain52 which runs over a sprocket 53 mounted on the shaft 28 and thesprocket 54 mounted on the power input shaft 55 of the gear box 51.

What is claimed is:

1. In a drawworks for use in a derrick having a crown block, atravelling block and a line having a soooling portion: supporting means:a spool rotatably carried by said supporting means, said s ool having asnoolin surface of a size to accommodate said soooling portion of saidline in a single laver; a line shaft: a driving shaft for said spool;speed chan e means through which said driving shaft is driven atdifferent speeds from said line shaft; a speed reducing transmissionconnection between said driving shaft and said spool whereby said spoolis driven at a speed slower than the speed of said driving shaft; afriction brake for controlling the rotation of said spool connected tosaid driving shaft; a power absorber for controlling the rotation ofsaid spool; and means for connecting said power absorber to said drivingshaft so that the power absorber will be operated at a speed higher thanthe speed of said spool.

2. In a drawworks for use in a derrick having a crown block, atravelling block and a line having a spooling portion: supporting means;a spool rotatably carried by said supporting means, said spool having aspooling surface of a size to accommodate said spooling portion of saidline in a single layer; a driving shaft supported in operative relationto said spool; a speed reducing transmission connection between saiddriving shaft and said spool whereby said spool is driven at a speedslower than the speed of said driving shaft; a friction brake forcontrolling the rotation of said spool connected by said driving shaft;a power absorber for controlling the rotation of said spool; and meansfor connecting said power absorber to said driving shaft so that thepower absorber will be operated at a speed higher than the speed of saidspool.

3. In a drawworks for use in a derrick having a crown block, atravelling block and a line having a spooling portion: supporting means;a spool rotatably carried by said supporting means, said spool having aspooling surface of a size to accommodate said spooling portion of saidline in a single layer; a line shaft; :1 driving shaft for said spool;speed change means through which said driving shaft is driven atdifferent speeds from said line shaft; a speed reducing gear trainconnecting said driving shaft and said spool whereby said spool isdriven at a speed slower than the speed of said driving shaft; afriction brake for controlling the rotation of said spool connected tosaid driving shaft; a power absorber for controlling the rotation ofsaid spool; and means for connecting said power absorber to said drivingshaft so that the power absorber will be operated at a speed higher thanthe speed of said spool.

4. In a drawworks for use in a derrick having a crown block, atravelling block and a line having a spooling portion: supporting means;a spool rotatably carried by said supporting means, said spool having aspooling surface of a size to accommodate said spooling portion of saidline in a single layer; a driving shaft supported in operativerelationto said spool; a speed reducing gear train connecting saiddriving shaft and said spool whereby said spool is driven at a speedslower than the speed of said driving shaft; a friction brake forcontrolling the rotation of said spool connected to said driving shaft;a power absorber for controlling the rotation of said spool; and meansfor connecting said power absorber to said shaft so that the powerabsorber will be operated at a speed higher than the speed of saidspool.

5. In a vdrawworks for use in a derrick having a crown block, atravelling block and a line having a spooling portion: supporting means;a spool rotatably carried by said supporting means, said spool having aspooling surface of a size to accommodate said spooling portion of saidline in a single layer; a line shaft; a driving shaft for said spool;speed change means through which said driving shaft is driven atdifferent speeds from said line shaft; a speed reducing transmissionconnection between said driving shaft and said spool whereby said spoolis driven at a speed slower than the speed of said driving shaft; afriction brake for positively controlling the rotation of said spool;transmission means connecting said friction brake to said spool tooperate said brake at a higher speed than said spool; a power absorber;and means for connecting said power absorber to said driving shaft sothat the power absorber will be operated at a speed higher than thespeed of said spool.

References Cited in the file of this patent UNITED STATES PATENTS

